Skin care compositions

ABSTRACT

Disclosed are skin care compositions that are emulsion formulations comprising an aqueous phase, an oil phase, at least one emulsifier, and an epichlorohydrin cross-linked glyceryl starch.

This apppcation is a continuation of U.S. patent application Ser. No.09/813,614, filed on Mar. 21, 2001 and now U.S. Pat. No. 6,391,290, fromwhich benefit of priority is hereby formally claimed.

BACKGROUND OF THE INVENTION

A wide variety of compositions are known in the art for providingcosmetic and/or pharmacologic benefits to human skin. Benefits soughtinclude, for example, prevention, treatment or amelioration ofenvironmental or age-related damage or deterioration of the skin,improved appearance by modifying surface characteristics, improved feelby moisturizing, and prevention or treatment of specific skin disorders.Many conventional cosmetic cream and lotion compositions are described,for example, in Sagarin, Cosmetics Science and Technology, 2nd Edition,Volume 1, Wiley lnterscience (1972), and Encyclopedia of ChemicalTechnology, Third Edition, Volume 7.

Starch derived from various plant sources has been commonly known in theart to provide a desirable skin feel in emulsions intended for topicaluse. While providing the desirable skin feel, the efficiency andperformance of unmodified starch can be erratic. This had led to thedevelopment of various types of cross-linked and surface modifiedstarches. One of these in wide use is modified with aluminumoctenylsuccinate; an example brand of this is trademarked Dri-Flo byNational Starch Inc. Although an improvement over unmodified starch, thematerial can cause excessive thickening of product when heated and thestability of some cold process emulsions (Pemulen systems) iscompromised with use of this material.

Accordingly, there is a need for a topical formulation containing amodified starch that will impart desirable skin feel upon application tothe skin, yet will also withstand the elevated temperatures duringformulation and not cause excessive thickening of the resultingformulation.

In addition to the need for such a topical formulation, it would beadvantageous to use these formulations as vehicles for both sunscreenand after sun formulations.

It is now generally recognized that exposure to solar radiation can haveadverse health consequences, sometimes not appearing until several yearsfollowing the exposure. Of course, the immediately appearing “sunburn”from an overexposure can itself be a serious acute health problem.

Many products are available to reduce the amount of solar ultravioletradiation received by the skin during exposure to the sun's rays.Typical product formulations are lotions, creams, ointments or gelscontaining chemical and/or physical barriers to ultraviolettransmission. These vary considerably in their abilities to protect theskin against the physical and biochemical effects of ultravioletradiation.

Earlier sunscreening formulations were designed to protect againstsunburn from a limited solar exposure period, while transmittingsufficient radiation to permit skin tanning. However, the current focusis on eliminating as much ultraviolet exposure as possible, it beingrecognized that skin tanning, while esthetically pleasing to some, is aclear indication of tissue damage from overexposure to solar radiation.It has been recently discovered that any amount of unprotected exposurecan potentially cause immune system suppression and lead to futurehealth problems, such as skin carcinomas and other dermatologicaldisorders.

The SPF (Sun Protection Factor) rating system has been developed toprovide consumer guidance in selecting suitable sunscreens for any givenoutdoor activity. In general, the SPF number approximately correspondsto the multiple of time during which the properly applied sunscreen willprevent obvious reddening of the skin, over the exposure time thatcauses unprotected skin to exhibit reddening. Thus, a person should beable to remain in the sun without visible effects for eight times theusual unprotected duration, if an SPF 8 sunscreen formulation has beenproperly applied. Of course, the duration of unprotected exposure whichproduces a visible effect on the skin varies from one individual toanother, due to differences in their skin cells. Currently popular arehigh-SPF “sunblocker” products, having SPF values of at least 30.

One particular disadvantage of sunscreen products is developing aformulation containing sunscreen active agents that does not impart anoily feel when applied to the user's skin. Accordingly, it would beadvantageous to have a formulation containing sunscreen active agentsthat imparts an elegant feel upon application to the user's skin.Similarly, non sunscreen emulsions can also have the disadvantage of anoily skin feel. Accordingly, it would also be advantageous to have a nonsunscreen formulation that imparts an elegant feel upon application tothe users skin, such as after sun and insect repellant formulations,either alone or in combination with a sunscreen active agent.

SUMMARY OF THE INVENTION

Accordingly the present invention provides an emulsion formulation fortopical application to the skin comprising an aqueous phase, an oilphase, at least one emulsifier, and an epichlorohydrin cross-linkedglyceryl starch.

The invention further provides an oil-in-water emulsion formulation fortopical application to the skin comprising an aqueous phase, an oilphase, at least one emulsifier, and an epichlorohydrin cross-linkedglyceryl starch.

The invention further provides a water-in-oil emulsion formulation fortopical application to the skin comprising an aqueous phase, an oilphase, at least one emulsifier, and an epichlorohydrin cross-linkedglyceryl starch.

The invention further provides an emulsion formulation for topicalapplication to the skin comprising an aqueous phase, an oil phase, atleast one emulsifier, an epichlorohydrin cross-linked glyceryl starchand at least one sunscreen active agent.

The invention further provides an oil-in-water emulsion formulation fortopical application to the skin comprising an aqueous phase, an oilphase, at least one emulsifier, an epichlorohydrin cross-linked glycerylstarch and at least one sunscreen active agent.

The invention also provides an oil-in-water formulation for topicalapplication to the skin comprising an aqueous phase, an oil phase, atleast one emulsifier, an epichlorohydirn cross-linked glyceryl starch,and an insect repellant.

Finally, the invention further provides an oil-in-water formulation fortopical application to the skin comprising an aqueous phase, an oilphase, at least one emulsifier, an epichlorohydrin cross-linked glycerylstarch, at least one sunscreen sunscreen active agent, and an insectrepellant.

BRIEF DESCRIPTION OF THE DRAWINGS

FIG. 1 is an analysis performed by Malvern Instruments concerning theparticle size distribution of the emulsion droplets contained in aformulation that contains Dri-Flo starch.

FIG. 2 is an analysis performed by Malvern Instruments concerning theparticle size distribution of the emulsion droplets contained in aformulation that contains the epichlorohydrin cross-linked glycerylstarch.

DETAILED DESCRIPTION OF THE INVENTION

Names given to chemical substances herein generally are either acceptedchemical names, or are trade organization or regulatory agency approvednames such as CTFA Adopted Names as listed in J. A. Wenninger et al.,Eds., CTFA International Cosmetic Ingredient Dictionary, Eighth Ed., TheCosmetic, Toiletry and Fragrance Association, Washington, D.C., 2000.

The term “percent by weight” as used herein means the percent by weightof the ingredient per weight of the overall formulation.

The term epichlorohydrin cross-linked starch refers to glyceryl starchthat has been chemically cross-linked by epichlorohydrin to produce astarch that has excellent tolerance to processing variables such as heatand shear. The starch has a desirable smooth texture and feel, andpossesses improved stability relative to other starches commonly knownin the art. The formulation maintains a viscosity profile that is lessvariable than that of other starches that are commonly known in the artthroughout formulation and shelf-life. The preferred epichlorohydrincross-linked glyceryl starch is sold under the trade name Vulca 90 or PC99-1054, available from National Starch & Chemical Corp., and under thetrade name Stabilex-M, available from INA Concepts, Charlotte, N.C. Theepichlorohydrin cross-linked glyceryl starch may be present in an amountof about 0.1 percent to about 50 percent by weight, preferably about 2percent to about 5 percent by weight, most preferably about 3 or 4percent by weight.

The epichlorohydrin cross-linked starch may be prepared according to theexamples of U.S. Pat. No. 4,237,271, issued in the name of Rayford, etal., which is hereby incorporated by reference in its entirety, andwhich discloses methods of manufacturing cross-linked starch halohydrinsand their nitrogen containing substitution products.

The epichlorohydrin cross-linked glyceryl starch is a modified cornstarch that is a fine whitish powder. Additionally, the starch can haveabout 13% maximum of water content, and a neutral pH in a 10% slurry.The starch can have a 0.5% maximum ash content. Moreover, it isadvantageous that the starch have low amounts of residue propylenechlorohydrins, in the magnitude of about 0.20 to about 30 ppm propylenechlorohydrins in the final product of the starch. As is known to one ofskill in the art, these amounts are subject to some variation. Forpersonal care applications, the starch may be irradiated prior toformulation to reduce the microbial load, as is well known in the art.

The term “emulsion” shall be used herein to identify oil-in-water (o/w)or water-in-oil (w/o) type dispersion formulations intended forapplication to the skin, particularly lotions and creams providingcosmetic or therapeutic benefits. The emulsions may contain any of anumber of desired “active” ingredients, including skin colorants, drugsubstances (such as anti-inflammatory agents, antibiotics, topicalanesthetics, antimycotics, keratolytics, etc.), skin protectants orconditioners, humectants, ultraviolet radiation absorbers, sunlesstanning agents and the like, depending on the intended uses for theformulations.

Techniques for forming o/w and w/o emulsions are very well known in theart. The present invention is not dependent upon any particularformulation technique, it being recognized that the choice of specificformulation components may well make necessary some specific formulationprocedure.

Suitable emulsifiers for one aspect of the invention are those known inthe art for producing oil-in-water and/or water-in-oil type emulsions.An aqueous external phase is preferred by many people for skin contact,since it is not as likely to produce an oily or greasy sensation when itis being applied, as is an emulsion having an oil external phase. Thetypical oil-in-water emulsifier has a hydrophilic-lipophilic balance(frequently abbreviated as “HLB”) value greater than about 9, as is wellknown in the art; however, this “rule” is known to have numerousexceptions. The chosen emulsifier, depending upon its chemical nature,will be a component of either the oil or aqueous phase, and assists withboth the formation and the maintenance, or stability, of the emulsion.Suitable emulsifiers for another aspect of the invention are those knownin the art for producing water-in-oil type emulsions. The typicalwater-in-oil emulsifier has a HLB value of about 4 to about 6, as iswell known in the art; however, this “rule” is also known to havenumerous exceptions. Selection of suitable water-in-oil emulsifiers iswell known in the formulation art.

Most of the widely used emulsifier systems for sunscreen formulationscan be used in the invention. Particularly preferred emulsifiers arePEG-8 Distearate available under the trade name of Emerest 2712 fromHenkel, PEG-5 Glyceryl Stearate available under the trade namePOEM-S-105 from Riken Vitamin Oil, PEG-6 Hydrogenated Castor Oil,available under the trade name Sabowax ELH6 from Sabo, PEG-6 Oleate,available under the trade name STEPAN PEG-300 MO from Stepan, SorbitanSesquioleate, available under the trade name Arlacel 83 and Arlacel Cfrom ICI Surfactants, TEA-Stearate, available under the trade name ofCetasal from Gaftefosse S.A. Another preferred emulsifier is neutralizedcetyl phosphate, available under the trade name Amphisol A from LaRoche.Most preferred is an Acrylate/C₁₀-C₃₀ alkyl acrylate cross polymer ofC₁₀₋₃₀ alkyl acrylates and one or more monomers of acrylic acid,methacrylic acid or one of their simple esters crosslinked within allylether of sucrose or an allyl ether of pentaerythritol, available underthe trade names of Pemulen TR from B.F. Goodrich. The amount ofemulsifier used in the present invention is present in an amount ofabout 0.1 to about 10% by weight, preferably about 0.5 percent to about5 percent by weight, most preferably about 2 percent to about 4 percentby weight. The choice of an emulsifier is well within ordinary skill inthe art and is not a critical aspect of the invention. Additionalpreferred emulsifiers that may be employed include SorbitanTriisostearate available under the trade name Crill 6 from CrodaOleochemicals, and Polyglyceryl-3 Distearate available under the tradename Cremophor GS 32 from BASF.

Notwithstanding the Examples as set forth below, compositions of thepresent invention containing the epichlorohydrin cross-linked starch maybe formulated by dispersing the epichlorohydrin cross-linked starch intothe oil phase of the formulation when manufacturing the compositions ofthe present invention, and then combining this phase with the waterphase in forming an oil-in-water emulsion within the scope of thepresent invention. Many variations of formulating the compositions ofthe present invention exist, and all are considered within the scope ofthe present invention.

As is known in the art, it is preferred that the individual emulsiondroplets have a small and uniform size because these properties resultin a more stable emulsion. Conversely, a broad particle sizedistribution indicates that the interfacial tension between the dropletshas not been substantially reduced, and thus the droplets tend tocoalesce and form agglomerations that result in an unstable emulsion.

An analysis performed by Malvern Instruments comparing Dri-Flo starch tothe epihlorohydin cross-linked glyceryl starch of the present inventionis shown in FIGS. 1 and 2. In FIG. 1, the formulation containing theDri-Flo starch has an emulsion droplet diameter varying over a wideparticle size range of from about 1 micron to about 100 microns. Thereis a 90% distribution of particle size below about 83 microns asindicated in FIG. 1 and the accompanying analysis below.

As indicated in FIG. 2, however, there is a much narrower distributionof particle size with 90% of the emulsion droplets having a particlesize of less than about 10 microns in a formulation containing theepichlorohydrin cross-linked glyceryl starch of the present invention.

Thus, while not intending to be bound by any theory of operability, itis believed that these characteristics provide the desired enhanced skinfeel and improved processability and stability of formulationscontaining the epichlorohydrin cross-linked glyceryl starches of thepresent invention.

An analysis was performed on the two formulations using a shaker. Theformulations were pre-heated at 40° C. for two hours and then shaken at180 rpm at 40° C. Qualitative assessment was made at 2 hour intervalsfor a period of up to 8 hours. The data is presented below in Table 1.The lack of the presence of oil (N/O) is indicative of improvedstability of the formulation over time.

TABLE 1 Oil First Oil Oil in Squeezed Description Seen Tube Up Hours at180 rpm @ 40 C. (2.0 hr preheat then shake, Read every 2 hours up to 8hours CT oil free Faces Lotion SPF30 containing 8 8 8 Dri-Flo CT oilfree Faces Lotion SPF30 containing N/O N/O N/O Vulca 90

As is evident, the formulation containing the epichlorohydrincross-linked glyceryl starch of the present invention had no oil at theend of testing, while the formulation containing the Dri-Flo evidencedphase separation at 8 hours.

A second test was performed and the results are presented below in Table2.

TABLE 2 Oil Oil in Squeezed Description First Oil Tube Up Hours at 180rpm @ 40 C. (2.0 hr preheat then shake, Read every 2 hours up to 8 hoursCT oil free Faces Lotion SPF30 containing 2 2 2 Dri-Flo CT oil freeFaces Lotion SPF30 containing N/O 8 N/O Vulca 90

Again, the formulation containing the epichlorohydrin cross-linkedglyceryl starch of the present invention displayed markedly improvedresults relative to the formulation containing the Dri-Flo.

The formulations of the present invention provide an elegant feel uponapplication to the skin, while also possessing an improved ability towithstand high temperature and shear during formulation, as well as,improved stability over time relative to other skin care productscurrently manufactured.

The emulsions of the present invention have many advantages over priorart formulations. The emulsions of the present invention have improvedstability characteristics because of the smaller, more uniform emulsiondroplet size. There is a decrease in any large change in viscosity thatfrequently occurs with other types of starches. Moreover, the use of theepichlorohydrin cross-linked glyceryl starch provides a formulationhaving decreased viscosity fluctuation in the formulation and is moreinert as compared to other starches known in the art.

For purposes of the present invention, a “sunscreen active agent” shallinclude all of those materials, singly or in combination, that areregarded as acceptable for use as active sunscreening ingredients.Approval by a regulatory agency is generally required for inclusion ofactive agents in formulations intended for human contact, and thoseactive agents which have been or are currently approved for sunscreenuse in the United States include, without limitation, para aminobenzoicacid, avobenzone, cinoxate, dioxybenzone, homosalate, menthylanthranilate, octocrylene, octyl methoxycinnamate, octyl salicylate,oxybenzone, padimate O, phenylbenzimidazole sulfonic acid,sulisobenzone, trolamine salicylate, titanium dioxide, zinc oxide,diethanolamine methoxycinnamate, digalloy trioleate, ethyldihydroxypropyl PABA, glyceryl aminobenzoate, lawsone withdihydroxyacetone, red petrolatum.

Particularly preferred sunscreen active agents include homomenthylsalicylate available under the trade name Uniderm Homsal from UniversalPreserv-A-Chem, Benzophenone-3, available under the trade name Escalol567 from ISP VanDyk, Uvinul MS-40 from BASF and Uvasorb MET/C from 3VInc., Octyl Salicylate available under the trade name Neo Heliopan OSfrom Haarmann & Reimer, Octocrylene available under the trade nameUvinul N-539-SG from BASF and the trade name Neo Heliopan 303 fromHaarmann & Reimer, and Octyl methoxcinnamate, available under the tradename Parsol MCX from Givaudon Roure and LaRoche, or mixtures thereof.

It is typical to use combinations of two or more sunscreen ingredientsin a formulation, to achieve higher levels of ultraviolet absorption orto provide useful absorption over a wider range of ultravioletwavelengths than can be the case with a single active component. Severalother sunscreen active ingredients are accepted for use in othercountries and are also considered to be within the scope of the presentinvention.

Insect repelling components are desirable in sunscreening emulsions,since the emulsions are normally used primarily by persons engaged inoutdoor activities. The most widely used active agent for personal careproducts is N,N-Diethyl-m-toluamide, frequently called “DEET” andavailable in the form of a concentrate containing at least about 95percent DEET. Other synthetic chemical repellents include dimethylphthalate, ethyl hexanediol, indalone, di-n-propylisocinchoronate,bicycloheptene, dicarboximide and tetrahydrofuraldehyde. Certainplant-derived materials also have insect repellent activity, includingcitronella oil and other sources of citronella (including lemon grassoil), limonene, rosemary oil and eucalyptus oil. Choice of an insectrepellent for incorporation into the sunscreen emulsion will frequentlybe influenced by the odor of the repellent. The amount of repellentagent used will depend upon the choice of agent; DEET is useful at highconcentrations, such as up to about 15 percent or more, while some ofthe plant-derived substances are typically used in much lower amounts,such as 0.1 percent or less.

As used herein, an after sun emulsion formulation is defined as aformulation that can be administered after a user has been in the sunfor any amount of time that provides a soothing or healing effect thatis pleasant to the user. Such a formulation can contain, for instance,aloe vera, vitamins A and E, etc.

The compositions of the present invention may contain a wide range ofadditional, optional components. The CTFA Cosmetic Ingredient Handbook,Seventh Edition, 1997 and the Eighth Edition, 2000, which isincorporated by reference herein in its entirety, describes a widevariety of cosmetic and pharmaceutical ingredients commonly used in skincare compositions, which are suitable for use in the compositions of thepresent invention. Examples of these functional classes disclosed inthis reference include: absorbents, abrasives, anticaking agents,antifoaming agents, antioxidants, binders, biological additives,buffering agents, bulking agents, chelating agents, chemical additives,colorants, cosmetic astringents, cosmetic biocides, denaturants, drugastringents, external analgesics, film formers, fragrance components,humectants, opacifying agents, pH adjusters, plasticizers,preservatives, propellants, reducing agents, skin bleaching agents,skin-conditioning agents (emollient, humectants, miscellaneous, andocclusive), skin protectants, solvents, foam boosters, hydrotropes,solubilizing agents, suspending agents (nonsurfactant), sunscreenagents, ultraviolet light absorbers, waterproofing agents, and viscosityincreasing agents (aqueous and nonaqueous).

Water is employed in amounts effective to form the emulsion. It isgenerally preferred to use water which has been purified by processessuch as deionization or reverse osmosis, to improve the batch-to-batchformulation inconsistencies which can be caused by dissolved solids inthe water supply. The amount of water in the emulsion or composition canrange from about 15 percent to 95 weight percent, preferably from about45 to 75 percent, most preferably from about 60 percent to about 75percent.

An emollient is an oleaginous or oily substance which helps to smoothand soften the skin, and may also reduce its roughness, cracking orirritation. Typical suitable emollients include mineral oil having aviscosity in the range of 50 to 500 centipoise (cps), lanolin oil,coconut oil, cocoa butter, olive oil, almond oil, macadamia nut oil,aloe extracts such as aloe vera lipoquinone, synthetic jojoba oils,natural sonora jojoba oils, safflower oil, corn oil, liquid lanolin,cottonseed oil and peanut oil. Preferably, the emollient is acocoglyceride, which is a mixture of mono, di and triglycerides of cocoaoil, sold under the trade name of Myritol 331 from Henkel KGaA, orDicaprylyl Ether available under the trade name Cetiol OE from HenkelKGaA or a C₁₂-C₁₅ Alkyl Benzoate sold under the trade name Finsolv TNfrom Finetex. One or more emollients may be present ranging in amountsfrom about 1 percent to about 10 percent by weight, preferably about 5percent by weight. Another suitable emollient is DC 200 Fluid 350, asilicone fluid, available Dow Corning Corp.

Other suitable emollients include squalane, castor oil, polybutene,sweet almond oil, avocado oil, calophyllum oil, ricin oil, vitamin Eacetate, olive oil, silicone oils such as dimethylopolysiloxane andcyclomethicone, linolenic alcohol, oleyl alcohol, the oil of cerealgerms such as the oil of wheat germ, isopropyl palmitate, octylpalmitate, isopropyl myristate, hexadecyl stearate, butyl stearate,decyl oleate, acetyl glycerides, the octanoates and benzoates of(C₁₂-C₁₅) alcohols, the octanoates and decanoates of alcohols andpolyalcohols such as those of glycol and glyceryl, ricinoleates esterssuch as isopropyl adipate, hexyl laurate and octyl dodecanoate,dicaprylyl maleate, hydrogenated vegetable oil, phenyltrimethicone,jojoba oil and aloe vera extract.

Other suitable emollients which are solids or semi-solids at ambienttemperatures may be used. Such solid or semi-solid cosmetic emollientsinclude glyceryl dilaurate, hydrogenated lanolin, hydroxylated lanolin,acetylated lanolin, petrolatum, isopropyl lanolate, butyl myristate,cetyl myristate, myristyl myristate, myristyl lactate, cetyl alcohol,isostearyl alcohol and isocetyl lanolate. One or more emollients canoptionally be included in the formulation.

A humectant is a moistening agent that promotes retention of water dueto its hygroscopic properties. Suitable humectants include glycerin,polymeric glycols such as polyethylene glycol and polypropylene glycol,mannitol and sorbitol. Preferably, the humectant is Sorbitol, 70% USP orpolyethylene glycol 400, NF. One or more humectants can optionally beincluded in the formulation in amounts from about 1 percent to about 10percent by weight, preferably about 5 percent by weight.

A dry-feel modifier is an agent which when added to an emulsion, impartsa “dry feel” to the skin when the emulsion dries. Dry feel modifiers canbe used in addition to the epichlorohydrin cross-linked glyceryl starchused in the formulation of the present invention. Dry feel modifiers caninclude talc, kaolin, chalk, zinc oxide, silicone fluids, inorganicsalts such as barium sulfate, surface treated silica, precipitatedsilica, fumed silica such as an Aerosil available from Degussa Inc. ofNew York, N.Y. U.S.A.

It may be advantageous to incorporate additional thickening agents, suchas, for instance, Carbopol Ultrez, or alternatively, Carbopol ETD 2001,available from the B.F. Goodrich Co. The selection of additionalthickening agents is well within the skill of one in the art.

A waterproofing or water resistance agent is a hydrophobic material thatimparts film forming and waterproofing characteristics to an emulsion. Asuitable waterproofing agent is a copolymer of vinyl pyrollidone andeicosene and dodecane monomers such as Ganex V 220 and Ganex V 216Polymers, respectively, trade names of ISP Inc. of Wayne, N.J. U.S.A.Still other suitable waterproofing agents include polyurethane polymer,such as Performa V 825 available from New Phase Technologies andpolyanhydride resin No. 18 available under the trade name PA-18 fromChevron. The waterproofing agent is used in amounts effective to allowthe sunscreen to remain effective on the skin after exposure tocirculating water for at least 40 minutes for water resistance and atleast 80 minutes for waterproofing using the procedures described by theU.S. Food and Drug Administration in “Sunscreen Drug Products for OTCHuman Use,” Federal Register, Vol. 43, Aug. 25, 1978, Part 2, pp.38206-38269.

An antimicrobial preservative is a substance or preparation whichdestroys, or prevents or inhibits the proliferation of, microorganismsin the sunscreen composition, and which may also offer protection fromoxidation. Preservatives are frequently used to make self-sterilizing,aqueous based products such as emulsions. This is done to prevent thedevelopment of microorganisms that may be in the product from growingduring manufacturing and distribution of the product and during use byconsumers, who may further inadvertently contaminate the products duringnormal use. Typical preservatives include the lower alkyl esters ofpara-hydroxybenzoates (parabens), especially methylparaben,propylparaben, isobutylparaben and mixtures thereof, benzyl alcohol,phenyl ethyl alcohol and benzoic acid. The preferred preservative isavailable under the trade name of Germaben II from Sutton. One or moreantimicrobial preservatives can optionally be included in an amountranging from about 0.001 to about 10 weight percent, preferably about0.05 to about 1 percent.

An antioxidant is a natural or synthetic substance added to thesunscreen to protect from or delay its deterioration due to the actionof oxygen in the air (oxidation). Anti-oxidants prevent oxidativedeterioration which may lead to the generation of rancidity andnonenyzymatic browning reaction products. Typical suitable antioxidantsinclude propyl, octyl and dodecyl esters of gallic acid, butylatedhydroxyanisole (BHA, usually purchased as a mixture of ortho and metaisomers), butylated hydroxytoluene (BHT), nordihydroguaiaretic acid,Vitamin A, Vitamin E and Vitamin C. One or more antioxidants canoptionally be included in the sunscreen composition in an amount rangingfrom about 0.001 to about 5 weight percent, preferably about 0.01 toabout 0.5 percent.

Chelating agents are substances used to chelate or bind metallic ions,such as with a heterocylic ring structure so that the ion is held bychemical bonds from each of the participating rings. Suitable chelatingagents include ethylene diaminetetraacetic acid (EDTA), EDTA disodium,calcium disodium edetate, EDTA trisodium, EDTA tetrasodium and EDTAdipotassium. One or more chelating agents can optionally be included inthe sunscreen in amounts ranging from about 0.001 to about 0.2 weightpercent preferably about 0.01% weight percent.

Fragrances are aromatic substances which can impart an aestheticallypleasing aroma to the sunscreen composition. Typical fragrances includearomatic materials extracted from botanical sources (i.e., rose petals,gardenia blossoms, jasmine flowers, etc.) which can be used alone or inany combination to create essential oils. Alternatively, alcoholicextracts may be prepared for compounding fragrances. However, due to therelatively high costs of obtaining fragrances from natural substances,the modern trend is to use synthetically prepared fragrances,particularly in high-volume products. The preferred fragrances for usein the present invention are Fragrance SZ-2108 and Fragrance SZ-1405available from Sozio, Inc.. One or more fragrances can optionally beincluded in the sunscreen composition in an amount ranging from about0.001 to about 5 weight percent, preferably about 0.01 to about 0.5percent by weight.

A pH modifier is a compound that will adjust the pH of a formulation toa lower, e.g., more acidic pH value, or to a higher, e.g., more basic pHvalue. The selection of a suitable pH modifier is well within theordinary skill of one in the art.

The invention will be further described by means of the followingexamples, which are not intended to limit the invention, as defined bythe appended claims, in any manner.

In each of the foregoing examples, the dispersator is of the open shearblade type, for instance, a Premier Model 50 dispersator.

EXAMPLE 1

Percent Ingredient W/W Description Part A 56.86 USP Purified Water 0.12Carbopol Ultrez 10 Part B 5.00 Sorbitol Solution, 70% USP 0.01 DisodiumEDTA 1.11 Triethanolamine, 99% NF Part C 0.05 Vitamin E, DL AlphaTocopherol 0.80 Polyanhydride Resin PA-18 0.80 Stearic Acid, NF TripPressed 0.60 Cremophor GS-32 1.50 Crill 6 12.00 Homomenthyl Salicylate;Homosal 5.50 UVASORB; UVINUL M40; Escalol 567 5.00 Neo Heliopan OS 0.40D.C. 200 Fluid 350 CS 0.70 Ganex V220 Polymer 5.00 Octocrylene Part D0.05 Fragrance SZ-2108 1.00 Germaben II Part E 3.00 Vulca PC99-1054

The formulation is manufactured by adding the carbopol to the water ofPart A while stirring and mixing until the mixture is clear andlump-free. Next, the ingredients of Part B are added to Part A and theresulting mixture is heated to 170-180° F. The temperature of themixture is maintained. Next, the ingredients of Part C are mixedtogether, with the exception of the PA-18 and D.C. 200 Fluid, and heatedto 180-185° F. The PA-18 is sprinkled into Part C and mixed until thePA-18 is dissolved. Finally, the D.C. 200 fluid is added to the mixtureof Part D. Next, the hot oil phase of Step 3 is added to the hot waterphase of Step 2. When the batch cools to less than 122° F., part D isadded to the mixture and mixing is continued until the batch reachesroom temperature. Next part E is slowly sprinkled into the emulsion. QSbatch and mix well.

EXAMPLE 2

Percent Ingredient W/W Description Part A 58.36 USP Purified Water 0.12Carbopol Ultrez 10 Part B 5.00 Sorbitol Solution, 70% USP 0.01 DisodiumEDTA 1.11 Triethanolamine, 99% NF Part C 0.05 Vitamin E, DL AlphaTocopherol 0.80 Polyanhydride Resin PA-18 0.80 Stearic Acid, NF TripPressed 0.60 Cremophor GS-32 1.50 Crill 6 12.00 Homomenthyl Salicylate;Homosal 5.50 UVASORB; UVINUL M40; Escalol 567 5.00 Neo Heliopan OS 0.40D.C. 200 Fluid 350 CS 0.70 Ganex V220 Polymer 5.50 Octocrylene Part D0.05 Fragrance SZ-2108 1.00 Germaben II Part E 3.00 Vulca PC99-1054

The formulation is manufactured by adding the carbopol to the water ofPart A while stirring and mixing until the mixture is clear andlump-free. Next, the ingredients of Part B are added to Part A and theresulting mixture is heated to 170-180° F. The temperature of themixture is maintained. Next, the ingredients of Part C are mixedtogether, with the exception of the PA-18 and D.C. 200 Fluid, and heatedto 180-185° F. The PA-18 is sprinkled into Part C and mixed until thePA-18 is dissolved. Finally, the D.C. 200 fluid is added to the mixtureof Part D. Next, the hot oil phase of Step 3 is added to the hot waterphase of Step 2. When the batch cools to less 122° F., part D is addedto the mixture and mixing is continued until the batch reaches roomtemperature. Next part E is slowly sprinkled into the emulsion. QS batchand mix well.

EXAMPLE 3

Percent Ingredient W/W Description Part A 55.66 USP Purified Water 3.00Glycerin, USP, 99% Part B 5.00 Neo Heliopan OS 5.00 Myritol 331 6.00UVASORB; UVINUL M40; Escalol 567 12.00 Homomenthyl Salicylate; Homosal7.50 Parsol MCX or Neoheliopan AV 1.00 Emulgade PL 68/50 Part C 0.10Pemulen TR-2 Part D 0.75 10% Sodium Hydroxide Part E 0.05 FragranceSZ-2108 1.00 Germaben II Part F 3.00 Vulca PC99-1054

In a container large enough to hold the entire batch, add theingredients of Part A. Mix completely and heat to 175° F. In a separatecontainer, add the ingredients of Part B and heat to 180° F. Sprinkle inPart C into the container containing Part B. Add the mixture of Parts Band C into Part A and thoroughly mix. Add Part D to the resultingmixture. Allow the mixture to cool to 122° F., and then add Part E. Mixthoroughly and allow the mixture to cool to room temperature. Uponcooling to room temperature, slowly sprinkle in Part F and mix well. QSthe batch with water and mix thoroughly.

EXAMPLE 4

Percent Ingredient W/W Description Part A 55.85 USP Purified Water 3.00Glycerin, USP, 99% Part B 5.00 Neo Heliopan OS 5.00 Myritol 331 6.00Uvasorb; Uvinul M40; Escalol 567 12.00 Homomenthyl Salicylate; Homosal7.50 Parsol MCX or Neo Heliopan AV 1.00 Emulgade PL 68/50 Part C 0.10Pemulen TR-2 Part D 0.50 10% Sodium Hydroxide Part E 1.00 Germaben II0.05 Fragrance SZ-2108 Part F 3.00 Vulca PC99-1054

In a container large enough to hold the entire batch, add ingredients ofPart A. Mix completely and heat to 175° F. In a separate container, addthe ingredients of Part B and heat to 180° F. Sprinkle in Pemulen TR 2of Part C into Part B. Add Part B/Part C mixture to Part A with thoroughmixing. Add 10% NaOH of Part D. When cooled to 122° F., add Part E. Mixthoroughly and slowly sprinkle in Part F while mixing. When cooled toroom temperature, QS the batch with water and homogenize for 5 minutes.

EXAMPLE 5

Percent Ingredient W/W Description Part A 56.00 USP Purified Water 3.00Glycerin, USP, 99% Part B 5.00 Neo Heliopan OS 5.00 Myritol 331 6.00Uvasorb; Uvinul M40; Escalol 567 12.00 Homomenthyl Salicylate; Homosal7.50 Parsol MCX or Neo Heliopan AV 1.00 Emulgade PL 68/50 Part C 0.10Pemulen TR-2 Part D 0.35 10% Sodium Hydroxide Part E 1.00 Germaben II0.05 Fragrance SZ-2108 Part F 3.00 Vulca PC99-1054

In a container large enough to hold the entire batch, add ingredients ofPart A. Mix completely and heat to 175° F. In a separate container, addthe ingredients of Part B and heat to 180° F. Sprinkle in Pemulen TR 2of Part C into Part B. Add Part B/Part C mixture to Part A with thoroughmixing. Add 10% NaOH of Part D. When cooled to 122° F., add Part E. Mixthoroughly and slowly sprinkle in Part F while mixing. When cooled toroom temperature, QS the batch with water and homogenize for 5 minutes.

EXAMPLE 6

Percent Ingredient W/W Description Part A 56.89 USP Purified Water 0.09Carbopol Ultrez 10 Part B 5.00 Sorbitol Solution, 70% USP 0.01 DisodiumEDTA 1.11 Triethanolamine, 99% NF Part C 0.05 Vitamin E, DL AlphaTocopherol 0.80 Polyanhydride Resin PA-18 0.80 Stearic Acid, NF TripPressed 0.60 Cremophor GS-32 1.50 Crill 6 12.00 Homomenthyl Salicylate;Homosal 5.50 UVASORB; UVINUL M40; Escalol 567 5.00 Neo Heliopan OS 0.40D.C. 200 Fluid 350 CS 0.70 Ganex V220 Polymer 5.50 Octocrylene Part D0.05 Fragrance SZ-2108 1.00 Germaben II Part E 3.00 Vulca PC99-1054

The formulation is manufactured by adding the carbopol to water of PartA while stirring and mixing until the mixture is clear and lump-free.Next, the ingredients of Part B are added to Part A and the resultingmixture is heated to 170-180° F. The temperature of the mixture ismaintained. Next, the ingredients of Part C are mixed together, with theexception of the PA-18 and D.C. 200 Fluid, and heated to 180-185° F. ThePA-18 is sprinkled into Part C and mixed until the PA-18 is dissolved.Finally, the D.C. 200 fluid is added to the mixture of Part D. Next, thehot oil phase of Step 3 is added to the hot water phase of Step 2. Whenthe batch cools to less than 122° F., Part D is added to the mixture andmixing is continued until batch reaches room temperature. Next Part E isslowly sprinkled into the emulsion. QS the batch and mix well.

EXAMPLE 7

Percent Ingredient W/W Description Part A 56.88 USP Purified Water 0.10Carbopol Ultrez 10 Part B 5.00 Sorbitol Solution, 70% USP 0.01 DisodiumEDTA 1.11 Triethanolamine, 99% NF Part C 0.05 Vitamin E, DL AlphaTocopherol 0.80 Polyanhydride Resin PA-18 0.80 Stearic Acid, NF TripPressed 0.60 Cremophor GS-32 1.50 Crill 6 12.00 Homomenthyl Salicylate;Homosal 5.50 UVASORB; UVINUL M40; Escalol 567 5.00 Neo Heliopan OS 0.40D.C. 200 Fluid 350 CS 0.70 Ganex V220 Polymer 5.50 Octocrylene Part D0.05 Fragrance SZ-2108 1.00 Germaben II Part E 3.00 Vulca PC99-1054

Add Carbopol to water of Part A while stirring and mix until the mixtureis clear and lump-free. Add the ingredients of Part B to Part A and heatto 170-180° F. Maintain the temperature of the mixture. Mix theingredients of Part C together except for PA-18 and D.C. 200 fluid, andheat to 180-185° F. Sprinkle in the PA-18 and mix until the PA-18 isdissolved, and then add the D.C. 200 fluid. Add the hot oil phase ofStep 3 to the hot water phase of Step 2. When the batch cools to lessthan 122° F., add Part D and continue mixing until the batch reachesroom temperature. Slowly sprinkle Part E into the emulsion. QS the batchand mix well.

EXAMPLE 8

Percent Ingredient W/W Description Part A 46.81  USP Purified Water 0.30Pemulen TR-2 0.01 Disodium EDTA 0.10 Tween 20 1.50 Germazide MPB Part B2.00 Parsol 1789 5.00 Octocrylene 4.00 Uvasorb; Uvinul M40; Escalol 5675.00 Neo Heliopan OS 8.00 Homomenthyl Salicylate; Homosal 6.00 Cetiol OE2.00 D.C. 200 Fluid 350 CS 2.00 Ganex v216 0.01 Aloe Vera Lip-/Aloe OilExtr. 0.01 Vitamin E, DL Alpha Tocopherol Part C 10.00  USP PurifiedWater 0.25 Triethanolamine, 99% NF Part D 4.00 Vulca PC99-1054 Part E QSUSP Purified Water

Add the ingredients of Part A except for the Pemulen to a beaker andmix. Slowly sprinkle in the Pemulen and mix until it is completelydispersed. Add the ingredients of Part B to a second beaker and heatwith mixing to 135-145° F. until all of the Oxybenzone has dissolved.Add the oil phase to the water phase and mix with a high speed disperserfor a minimum of 15 minutes at 2700 rpms. Combine the water and TEA ofPart of C and mix until all of the TEA has dissolved. The resultingsolution should be clear. Change to a 3 blade prop and continue mixingthe primary emulsion of step 4. Add the TEA solution of Step 5 to theprimary emulsion and mix vigorously for 3 minutes. Slowly sprinkle inthe Vulca PC99-1054 of Part D and stir vigorously for at least 15minutes. QS the batch to weight with the water of Part E and mix for 1minute.

EXAMPLE 9

Percent Ingredient W/W Description Part A 48.54  USP Purified Water 0.30Pemulen TR-2 3.00 Polyethylene Glycol 400, NF 0.20 Methylparaben, NF0.01 Disodium EDTA 0.10 Tween 20 0.50 Benzyl Alcohol, NF Part B 2.00Parsol 1789 5.00 Octocrylene 4.00 Uvasorb; Uvinul M40; Escalol 567 5.00Neo Heliopan OS 8.00 Homomenthyl Salicylate; Homosal 6.00 Cetiol OE 2.00D.C. 200 Fluid 350 CS 2.00 Ganex V-216 0.10 Propylparaben, NF Part C10.00  USP Purified Water 0.25 Triethanolamine, 99% NF Part D 3.00 VulcaPC99-1054 Part E QS USP Purified Water

Add the ingredients of Part A except the Pemulen to a beaker and mix.Slowly sprinkle in the Pemulen and mix until it is completely dispersed.Add the ingredients of Part B to a second beaker and heat with mixing to135-145° F. until all of the Oxybenzone has dissolved. Add the oil phaseto the water phase and mix with a high speed disperser for a minimum of15 minutes at 2700 rpms. Combine the water and TEA of Part of C and mixuntil all has dissolved. The resulting solution should be clear. Changeto a 3 blade prop and continue mixing the primary emulsion of Step 4.Add the TEA solution of Step 5 to the primary emulsion and mixvigorously for 3 minutes. Slowly sprinkle in the Vulca PC99-1054 of PartD and stir vigorously for at least 15 minutes. QS the batch to weightwith the water of Part E and mix for 1 minute.

EXAMPLE 10

Percent Ingredient W/W Description Part A 47.54  USP Purified Water 0.30Pemulen TR-2 3.00 Polyethylene Glycol 400, NF 0.20 Methylparaben, NF0.01 Disodium EDTA 0.10 Tween 20 0.50 Benzyl Alcohol, NF Part B 2.00Parsol 1789 5.00 Octocrylene 4.00 Uvasorb; Uvinul M40; Escalol 567 5.00Neo Heliopan OS 8.00 Homomenthyl Salicylate; Homosal 6.00 Cetiol OE 2.00D.C.200 Fluid 350 CS 2.00 Ganex V-216 0.10 Propylparaben, NF Part C10.00  USP Purified Water 0.25 Triethanolamine, 99% NF Part D 4.00 VulcaPC99-1054 Part E QS USP Purified Water

Add the ingredients of Part A except the Pemulen to a beaker and mix.Slowly sprinkle in the Pemulen and mix until it is completely dispersed.Add the ingredients of Part B to a second beaker and heat with mixing to135-145° F. until all of the Oxybenzone has dissolved. Add the oil phaseto the water phase and mix with a high speed disperser for a minimum of15 minutes at 2700 rpms. Combine the water and TEA of Part C and mixuntil all has dissolved. The resulting solution should be clear. Changeto a 3 blade prop and continue mixing the primary emulsion of Step 4.Add the TEA solution of Step 5 to the primary emulsion and mixvigorously for 3 minutes. Slowly sprinkle in the Vulca PC99-1054 of PartD and stir vigorously for at least 15 minutes. QS the batch to weightwith the water of Part E and mix for 1 minute.

EXAMPLE 11

Percent Ingredient W/W Description Part A 49.54  USP Purified Water 0.30Pemulen TR-2 3.00 Polyethylene Glycol 400, NF 0.20 Methylparaben, NF0.01 Disodium EDTA 0.10 Tween 20 0.50 Benzyl Alcohol, NF Part B 2.00Parsol 1789 5.00 Octocrylene 4.00 Uvasorb; Uvinul M40; Escalol 567 5.00Neo Heliopan OS 4.00 Acetylated Lanolin Alcohol 2.00 Glucam P-20Distearate 7.00 Finsolv TN 2.00 D.C.200 Fluid 350 CS 2.00 Ganex V-2160.10 Propylparaben, NF Part C 10.00  USP Purified Water 0.25Triethanolamine, 99% NF Part D 3.00 Vulca PC99-1054 Part E QS USPPurified Water

Add the ingredients of Part A except the Pemulen to a beaker and mix.Slowly sprinkle in the Pemulen and mix until it is completely dispersed.Add the ingredients of Part B to a second beaker and heat with mixing to135-145° F. until all of the Oxybenzone has dissolved. Add the oil phaseto the water phase and mix with a high speed disperser for a minimum of15 minutes at 2700 rpms. Combine the water and TEA of Part C and mixuntil all has dissolved. The resulting solution should be clear. Changeto a 3 blade prop and continue mixing the primary emulsion of Step 4.Add the TEA solution of Step 5 to the primary emulsion and mixvigorously for 3 minutes. Add the Vulca PC99-1054 of Part D withvigorously agitation. Mix vigorously for at least 15 minutes. QS thebatch to weight with the water of Part E and mix for 1 minute. Hand-millthe entire batch.

EXAMPLE 12

Percent Ingredient W/W Description Part A 64.20 USP Purified Water 0.40Pemulen TR-1 0.15 Carbopol ETD 2001 0.20 Methylparaben, NF Part B 0.01Disodium EDTA Part C 3.00 Octocrylene 2.00 Parsol 1789 5.00 Neo HeliopanOS 10.00 Homomenthyl Salicylate; Homosal 0.05 Vitamin E, DL AlphaTocopherol 0.05 Aloe Vera Lipo-/Aloe Oil Extr. 0.10 Propylparaben, NF4.00 UVASORB; UVINUL M40; Escalol 567 2.00 Lexorez 200 Part D 1.00Benzyl Alcohol, NF Part E 0.34 Triethanolamine, 99% NF Part F 2.00 VulcaPC99-1054 5.00 Polyethylene Glycol 400, NF Part G 0.50 Fragrance SZ 1405

Using a prop mixer equipped with a small tooth blade, disperse thePemulen and Carbolpol ETD 2001 into the water of Part A using rapidmixing for five minutes, and then change to a 3 prong prop and mix untilthe mixture is free from lumps. Next, add the Methylparaben and mixwell. Add the Disodium EDTA of Part B to the Pemulen/Carbopol ETD 2001solution of Step 1 and mix well. In a beaker equipped with a prop mixer,combine the ingredients of Part C and heat to 120° F. with mixing untilthe Spectrasorb UV-9 is dissolved. Add the oil phase of Step 3 to theaqueous phase of Step 2 and mix well. Add the Benzyl alcohol of Part Dto the batch of Step 4 and mix well. Add the TEA of Part E and mixvigorously until an emulsion is formed. In a suitable sized beaker, addthe PEG 400 of Part F and begin mixing on a mechanical stirrer. Slowlysprinkle in the Vulca PC99-1054 and mix vigorously until it is welldispersed. Add the suspension of Step 7 to the batch of Step 6 withvigorous agitation for at least 15 minutes. Add the fragrance of Part Gand mix well.

EXAMPLE 13

Percent Ingredient W/W Description Part A 67.20 USP Purified Water 0.40Pemulen TR-1 0.15 Carbopol ETD 2001 0.20 Methylparaben, NF Part B 0.01Disodium EDTA Part C 3.00 Octocrylene 5.00 Neo Heliopan OS 2.00 Parsol1789 2.00 UVASORB; UVINUL M40; Escalol 567 10.00 Homomenthyl Salicylate;Homosal 0.05 Vitamin E, DL Alpha Tocopherol 0.05 Aloe Vera Lipo-/AloeOil Extr. 0.10 Propylparaben, NF 2.00 Lexorez 200 Part D 0.34Triethanolamine, 99% NF Part F 2.00 Vulca PC99-1054 5.00 PolyethyleneGlycol 400, NF Part G 0.50 Fragrance SZ 1405

Using a prop mixer equipped with a small tooth blade, disperse thePemulen and Carbolpol ETD 2001 into the water of Part A using rapidmixing for five minutes, and then change to a 3 prong prop and mix untilfree from lumps. Next, add the Methylparaben and mix well. Add theDisodium EDTA of Part B to the Pemulen/Carbopol ETD 2001 solution ofStep 1 and mix well. In a beaker equipped with a prop mixer, combine theingredients of Part C and heat to 120° F. with mixing until all of theingredients have dissolved. Add the oil phase of Step 3 to the aqueousphase of Step 2 and mix well. Add the TEA of Part D and mix vigorouslyuntil an emulsion is obtained. In a suitable sized beaker, add the PEG400 of Part F and begin mixing on a mechanical stirrer. Slowly sprinklein the Vulca PC99-1054 and mix until uniform. Add the suspension of Step6 to the batch of Step 5 with vigorous agitation for at least 15minutes. Add the fragrance of Part G and mix well.

What is claimed is:
 1. An emulsion formulation for topical applicationto the skin comprising: an aqueous phase, an oil phase, at least oneemulsifier, and an epichlorohydrin cross-linked glyceryl starch.
 2. Theformulation of claim 1, wherein the formulation is an oil-in wateremulsion.
 3. The formulation of claim 2, wherein the at least oneemulsifier is present in an amount of about 1 to about 10 percent byweight.
 4. The formulation of claim 1, wherein the formulation is awater-in-oil emulsion.
 5. The formulation of claim 4, wherein the atleast one emulsifier is present in an amount of about 1 to about 10percent by weight.
 6. The formulation of claim 1, wherein theepichlorohydrin cross-linked glyceryl starch is present in an amount ofabout 0.1 to about 50 percent by weight.
 7. The formulation of claim 6,wherein the epichlorohydrin cross-linked glyceryl starch is present inan amount of about 2 to about 4 percent by weight.
 8. The formulation ofclaim 1, further comprising at least one sunscreen active agent.